Means for magnetically retaining an insole and last in assembled alignment



R G. KLINE ETAL MEANS FOR MAGNETICALLY RETAINING AN INSOLE AND LAST IN ASSEMBLED ALIGNMENT Jan. 26, 1965 2 Sheets-Sheet 1- Original Filed May 23,

Jan. 26, 1965 R. G. -K l E ETAL 3,166,771

MEANS FOR MAGNETICALLY RETAINING AN INSOLE AND LAST IN ASSEMBLED ALIGNMENT Original Filed May 23. 1962 2 Sheets-Sheet 2 INVENTORS Fwy/7 90 C fi zJ/ws (/0 HA B. 25/ a Paeeerfljfaswae BY I mama, W ATTOR Y5 United States Patent 3,166,771 MEANS FOR MAGNETICALLY RETAINHQG AN IN- SULE AND LAST IN ASSEMELED ALIGNMENT Richard G. Kiine, Springfield, Md, and John B. Reid, Brighton, and Robert A. Spence, South Lincoln, Mass assignors to BainCorporation, Cambridge, Mass., a corporation of Massachusetts 7 Original application May 23,1962, Ser. No. 197,131, new Patent No. 3,697,381, dated July 16, 1963. Divided and this appiication Aug. 13, 1962., Ser. No. 224,266

13 Qiaims. (U1. 12-141) This application is a division of my copending application Serial No. 197,131, filed May 23, 1962, now Patent No. 3,097,381, granted July 16, 1963.

This invention generally relates to the manufacture of footwear, and more particularly to novel means for temporarily securing a shoe insole to the bottom of a related last as a step in the manufacturing procedure.

Re ardless of the fastening means employed, the insole must be firmly retained in aligned position on the last so as to withstand the severe lateral and normal stresses imposed during the lasting operation that tend to displace the insole relative to the last bottom. At the same time, the retaining means must'be such that upon completion of the lasting operation, it can be released to permit removal of the last from the shoe interior without leaving any vestiges of the fastening means to either discolor or permanently disfigure the foot contacting surface of the insole.

In the past, insoles: have customarily been secured to conventional wooden lasts by suitable tack fasteners driven directly through the insole into the last bottom in order, to retain the assembled components in aligned relation until completion of the lasting operation. The disadvantages of such a procedure are readily apparent in that each tack must be individually removed, either manually or by a mechanical tack puller, with the resultant destructive marring or gouging of the insole and permanent mutilation of the wooden last. Also, oc-

casional shearing or" the conventional tack head necessi tates separate inspection of aeach shoe for the purpose of detecting and removing the inibedded portion.

The desirability of replacing the customary t-ackfastener with some o her means to temporarily secure the insole to the last bottom has long been recognized by the industry. For example, the insole can be bonded directly to the last bottom by an adhesive'material, such as tape'which'must be subsequently stripped off, or by a thermoplastic resin that can be removed only through the application of either heat 'orvibr-ational shock. In either event the adhesive material cannot be reused and must be continually renewed thereby resulting in excessive waste.

It is therefore the primary purpose ofthis invention to detachably secure an insole to the bottom of a related last without perforating the foot contacting surfiace of the insole or interposing an adhesive material between the assembled components to'form a temporary bond that must be subsequently released either by stripping or through the application of external heat or by vibrational shock.

I A principal object .of the present invention resides in the utilization of a magnetic force for temporarily rein order to prevent relative displacementof the aligned components during the lasting operation.

A further object of this invention is the provision of specially designed magnets and magnetic materials constructed to resist and withstand the severe lateral and normal stresses imposed during the lasting operation that tend to displace the insole relative to the holding member and last.

A still further object of thepresent invention resides in the provision of specially designed magnets and magnetic materials which serve to secure an insole to the bot tom of a related last regardless of the surface contour of the latter component.

Another object of this invention is the provision of specially designed magnets and magnetic materials that may be used repeatedly without requiring replacement; which are thoroughly reliable, effective and relatively simple inconstruction, and otherwise well adapted to the purposes for which the same are intended.

Other objects and the entire scope of the present invention will become apparent from the following detailed description and by reference to the accompanying drawings. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modificatio-ns Within the spirit and scope of the invention will become apparent as the description herein progresses. Reference now being made to the accompanying drawings which form a part hereof, wherein like numerals referto similar parts throughout and in which:

FIGURE 1 is aside elevational View, partially in section, of an insole and related lastretained in assembled alignment by magnetic means in accordance with the present invention;

FIGURE 2 is a top plan view, partially in section, of the assembled insole and last illustrated in FIGURE 1;

FIGURE 3 is an end view, partially in section, of the assembled insole and last illustrated in FIGURE 1;

' FIGURE 4 is an exploded schematic view showing the insole positioned between a magnet imbedded in the last and a separate magnetic holding member;

FIGURE 5 is an exploded schematic view similar to FIGURE 4 except that the insole is positioned between" a strip 'of magnetic tape material applied directly to the last and a related magnetic holding member;

FIGURE 6 is'an explodedschematic view of a modifi ed embodiment wherein the holding member is in the form of-a strip of magnetic tape material applied along the innerface of the insole;

FIGURE '7 is an exploded schematiciview of another modified embodiment similar to FIGURE 6' except the FIGURE 9 is a top plan view, partially'in section, of

the assembledinsole and electro-magnetic last illustrated in FIGURE 8;

FIGURE 10 is an end view, partially in section, of the assembled insole and electromagnetic last illustrated in FIGURE 8;

FIGURE 11 is a sectional view of a magnetic holding Patented Jan. 26, 165

blend with the contoure the insole.

member constructed in accordance with the principles of the present invention;

FIGURE 12 is a sectional view similar to FIGURE 11 illustrating a modified imbedded magnet and associated holding member; and

FIGURE 13 is a sectional view of a modified magnetic holding member and associated magnetized last designed to eitectively resist any forces tending to laterally displace the insole relative to the holding member and last.

Referring now to the accompanying drawings, and particularly to the embodiment illustrated in FlGURES l to 3, inclusive, the numeral 2% generally designates a shoe last formed from wood, plastic or similar material having the usual toe and heel portions, 22 and 24, respectively, pivotally interconnected at 2:5 to permit collapsing and subsequent removal of the unit from a manufactured shoe in the customary manner. Located along the approximate longitudinal center line of the last Eli are a plurality of magnetic members 28 composed of ferromagnetic material Which becomes magnetized under the influence of a'magnetic held. The magnetic members 28 are imbedded in recesses countersunk in the toe and heel portions of the last and preferably are shaped to surface of the last bottom 30. If a heel plate is required, the central portion thereof must be removed to permit installation of the magnetic members 28, as shown in FIGURE 2, leaving only a marginalshoulder 31 of U-shaped outline. By performing the aforementioned modifications, a conventional last can be easily converted to receive the magnetic members.

Supported in superposed aligned relation with the bottom surface 3% of the last 2b is an insole 32 of conventional design which is retained in position by the force of magnetic attraction created between the magnetic members 2d and an associated holding member or keeper 34 containing a plurality of permanent magnets 3-6. Due

to the irregular surface contour of the last bottom, the magnetic holding member 34 must be capable of flexible movement in order to accommodate a variety of irregular profiles. Universal movement can be accomplished by either enclosing the magnetic components 36 within a flexible jacket 38 of non-magnetic material, such as plastic or cloth, or by directly interconnecting the individual magnets in any well known manner. Moreover, flexible strips of permanent magnetic material could also be utilized to achieve this effect. The holding member 34 is so arranged that when the permanent magnets 36 are moved into proximity of the magnetic members 28, magnetism will be induced and a magnetic field produced across the zone of attractive interaction forcing the insole 32 against the last bottom and retaining the latter components in constrained contact. When holding member 3 is withdrawn, attractive interaction between the magnets and magnetic member will'beinterrupted allowing the last to be separated from Conversely, it should be noted that permanent magnets 46 could be substituted for the magnetized members 23 imbedded in the last Zihas schematically illustrated in FIGURE 4 if the polarity between the holding member 34- and magnets 4b is such as to create an attractive magnetic force. As an alternate embodiment, a piece of single faced pressure sensitive tape 42 containing ferromagnetic material could be adhesively secured to the bottom surface 3b of the last 29 in place of the magnetic members 23, as shown in FIGURE 5. Conversely, the strip of pressure sensitive magnetic tape 42 could be. adhesively secured to either the outer or inner surfaces of the insole 32, as schematically illustrated in FIGURES 6 and 7, respectively, when permanent magnets as are imbedded in the last bottom 3%. Y

Electromagnets can also be utilized to produce the required magnetic field. As shown in FIGURE 8, a plurality of electro-magnets 44 imbedded in the last bottom 33 are electrically interconnected with one another and coupled to a suitable source of electric current through ase of the magnetic members 23 illustrated in rIGd l to 3, the central portion of the metallic heel plate has been removed so as not to interfere with the field created by the individual electro magnetic units 44. When the electromagnets 4d are energized, the field magnetizes and attracts the magnetic holding member 45 which in turn forces the insole 32 against the last bottom 39 retaining the same in assembled alignment and serving to resist separation until interruption of the electrical current supplied to lead wires 46. Again, the holding member 48 can be in the form of ferromagnetic material or a permanent magnet. Conversely, electro-magnets can be employed in the holding member to attract the magnetic material imbedded or secured to the last bottom. Thus, it should be understood that any combination of the preceding alternate embodiments can be employed without departing from the present invention. Moreover, the disclosed means for magnetically retaining an insole and related last in assembled alignment is applicable to all types of footwear made on a last, including men, women, children and infant shoes, slippers, moccasins, boots, or the like, whether right or left and regardless of size or type.

While the magnetic attraction developed between the holding member and associated magnetic member carried by the last will tend to resist separation of the insole from the last bottom in a direction normal to the surface of contact, tie assembled components can nevertheless become misaligned when subjected to a lateral force substantially parallel to the surface of contact. Accordingiy, one of the most important aspects of the present invention resides in the control of the magnitude and direction of magnetic flux produced by the magnetic held across the zone of attractive interaction where the insole and last come into contact. Referring now to FIGURE ll, the holding piece fill consists of a plurality of permanent magnets 53?. enclosed within a flexible, non-magnetic jacket 54. In order to concentrate the density of magnetic flux produced across the zone of attractive interaction, generally indicated by the numeral 56, the holding member 5% employs a pair of diverging extensions in the form of leg elements 58 and so which define a V-shaped channel 62. Holding member Si? is attracted downwardly towards the magnetic member 64 imbedded within the last 2%) forcing the insole 32 into intimate contact against the last bottom 38. The cross-sectional shape of the holding member Sil is such as to concentrate the magnetic ilux at the point where the localized field is deflected at an angle by the diverging leg portions 58 and 60 in its passage through the zone of attractive interaction 56. By reducing the cross-sectional area of legs 58 and 60, the flux density induced by the magnetic member 50 will be concentrated at the point where the supporting legs contact the insole 312, and by deflecting or changing the angle of the flux path, the holding member 50 will exert a restraining magnetic force at an angle to the normal so as to resist any lateral forces substantially parallel to the surface of contact which would tend to displace or misalign the insole 32 relative to the holding number Ell and last bottom 3%) during the manufacturing operation. Since the interacting attractive force induced by the magnetic member 5% develops a magnetic flux with components in both lateral and normal directions to the surface of contact established between the superposed insole and last, these resultant force components serve to maintain the holding member, insole and last in assembled alignment.

Referring now to FIGURE 12, in order to further concentrate and intensity the magnitude of magnetic flux, magnetic member 66 imbedded in the last 20 may be somewhat modified by employing permanent magnets surrounded by a magnetic core casing 68 of iron or similar ferromagnetic material which becomes magnetized through induction. In order to reduce leakage between the central portion of magnetic member 66 and holding member 70 lead Wires 46.

of magnetized material, a non-magnetic insulating material 72, such as plastic wood or the like, may be used to fill the intermediate gap between the magnetic member 66 and the contacting surface 30 of the last bottom. Thus, the magnetic field circuit will follow a path from the magnetic member 66 through the bushing or casing 68 and across the zone of attractive interaction where insole 32 is positioned relative to the lower leg 74 of the holding member 70 whereupon it will pass through the core '76 of magnetized material downwardly through the opposite leg 78 and again across the zones of attractive interaction to the opposite side of the casing 63. Since the central portion of the holding member 70 and magnetic member 66 are separated by an air gap 80 as well as non-magnetic material 72, the flux density will be intensified at the point where the magentic field passes through the insole 32 from the casing 68 to the diverging legs 74 and 78 of the holding member 70, which constitutes the zone of attractive magnetic interaction. While the magnetized bushing or casing 68 is shown with upwardly extending leg portions, it should be understood that the magnet 66 may be in the form of a curved or U-shaped member as long as the terminal portion which contacts the bottom surface 30 of the last is of reduced cross-sectional area in order to concentrate or localize the magnetic flux at that point.

With the foregoing in mind, it is also possible to vary the magnetic characteristics of the holding member 70 in the manner shown in FIGURE 13 by employing a permanent magnet 82 supported upon a pair of diverging legs 84 and 86 at its opposite edges which are composed of ferromagnetic material.. These legs are constructed so that the cross-sectional area of the leg is less than the cross-sectional area of the magnet thereby concentrating the magnetic flux at the areas of contact with the insole 32. Moreover, legs 84 and 86 flare outwardly with the maximum divergence at the point of contact with the insole so as to deflect or distort the magnetic field from the normal. An associated magnetized member 88 is shown imbedded in the last 20 with upwardly extending end portions 90 and 92 positioned adjacent the surface of contact 30. In order that the portion of the last above the magnetized member 88 retain the desired shape of the last bottom, the intermediate gap is filled with non-magnetic insulating material 94. By providing diverging legs 84 and 86, the magnetic fiux density can be concentrated and directed across the zone of attractive interaction which exists between legs 84 and 86 and the related magnetized portions 90 and 92 respectively. Thus, the circuit of the flux path or magnetic field wil be somewhat distorted at the zone of attractive interaction thereby more efiectively serving to resist any forces tending to laterally displace the insole 32 relative to the holding member 82 and last 20.

The present invention will thus be seen to completely and effectively accomplish the objects enumerated hereinabove. Since magnetic members and magnetized material may be employed in either the holding member or the last without affecting the principles of this invention, it will be realized that various changes and substitutions may be made to the specific embodiments disclosed herein for the purpose of illustrating the principles of this invention, without departing from these principles. Therefore, this invention includes all modifications encompassed within the spirit and scope of the following claims.

What is claimed is;

1. An assembly for holding footwear components on a last comprising a last and an associated holding member each of which are provided with separate magnetic means arranged to magnetically attract one another when said last and holding member are disposed in assembled relation, one of said magnetic means including means for localizing the magnetic attraction between it and the other 5 a magnetic means to restrain relative displacement of the assembled components.

2. An insole retaining assembly comprising an insole supporting last member, an insole holding member, one

member including an element of magnetizable material and the other member including. a permanent magnetic elementpsaid elements being arranged to magnetically interact with each other and establish a magnetic circuit for retaining said members'in assembled relation bymagnetic attraction.

3. An insole retaining assembly comprising an insole supporting last member, an insole holding member, one member including an element of magnetizable material and the other member including an electro-magnetic element, said elements being arranged to magnetically interact with each other and establish a magnetic circuit for retaining said members in assembled relation by magnetic attraction.

4. An insole retaining assembly comprising an insole supporting last member, an insole holding member, each member including separate magnets arranged to magnetically interact with one another and establish a magnetic circuit for retaining said members in assembled relation by magnetic attraction.

5. An insole retaining assembly as defined in claim 4, wherein at least one of said magnets is a permanent magnet.

6. An insole retaining assembly as defined in claim 4, wherein at least one of said magnets is an electromagnet.

7. A magnetic last for retaining an insole in assembled alignment therewith by magnetic attraction of an associ-' ated insole holding member comprising a last having an insole supporting portion, magnetic means mounted in magnetic means includes a permanent magnet.

9. A magnetic last as defined in claim 7, wherein said magnetic means includes an electro-magnet.

10. A magnetic last as defined in claim 7, wherein said magnetic means comprises a plurality of magnets disposed within said last which extend longitudinally along the insole supporting portion thereof. 7

11. A magnetic last as defined in claim 7, wherein said means for localizing the magnetic interaction includes a terminal extension of reduced cross-sectional area which forms part of the magnetic circuit and which terminates adjacent the insole supporting portion of said last.

12. An insole holding device for a magnetic last com prising an insole holding member, magnetizable material contained in said holding member and arranged to magnetically interact and establish a magnetic circuit with a magnetic last, said magnetizable material including means for localizing magnetic interaction with a magnetic last which comprises a pair of outwardly diverging terminal members of reduced cross-sectional area that form part of the magnetic circuit, said holding member including means for permitting the insole holding device to conform to the profile of a last.

13 An insole holding device for a magnetic last comprising an insole holding member, a magnet contained in said holding member and arranged to magnetically (References on following page) References Cites; by the Examiner UNITED STATES PATENTS Hill 12-1296 Blake 12-142 Hayden 101-4 Pym I2129.6 Batchelder 223-75 Schoenky 12-1296 Smith 269-8 X Ashlsy 12-334 Nolan 12-142 Sisson 269-8 Schecter et a1 36-25 Saffir 36-25 McCann 36-114 JORDAN FRANKLIN, Primary Examiner.

EDWARD V. BENHAM, Examiner. 

2. AN INSOLE RETAINING ASSEMBLY COMPRISING AN INSOLE SUPPORTING LAST MEMBER, AN INSOLE HOLDING MEMBER, ONE MEMBER INCLUDING AN ELEMENT OF MAGNETIZABLE MATERIAL AND THE OTHER MEMBER INCLUDING A PERMANENT MAGNETIC ELEMENT, SAID ELEMENTS BEING ARRANGED TO MAGNETICALLY INTERACT WITH EACH OTHER AND ESTABLISH A MAGNETIC CIRCUIT FOR RETAINING SAID MEMBERS IN ASSEMBLED RELATION BY MAGNETIC ATTRACTION. 